Vapor phase method of oil conversion



March 4, A1930- c. R. WAGNER VAPOR PHASE 4METHOD OF OIL CONVERSION FiledFeb. 21. 1928 d .uam FAUT... ....l x.. Amen, GJ .17.1. l., f....m...w.nwmmwm .,...u wam... Q w N m1 n 7/// KES@ alfkozun Patented Mar.4, 1930 UNITED STATES PATENT OFFICE .CARY R. WAGNER, OF CHICAGO,ILLINOIS, ASSIGNOR T0 GYRO PROCESS COMPANY, OF

DETROIT, MICHIGAN, 'A CORPORATION OF MICHIGAN VAPOR PHASE METHOD OF OILCONVERSION Application filed February 21, 1928. Serial No. 256,038.

This invention relates to improvements in the manufacture of motorfuels, and has particular reference to an improved vapor phase method ofproducing low boiling hydrocarbon compounds from relatively higherboiling point compounds. t

In accordance with the present invention a method of cracking isprovided consisting in passing a current of oil vapor through a tubularconverting element, 'within which element there is positioned a core ofa catalytic or contact material, and wherein provision is made forheating the current of oil vapor during its travel through theconverting element and around said core so that when such oil vapor isdischarged from the converting element it attains a temperature inexcess of 10000 Fah.

In the operation of va vapor phase system of this kind it has been thepractice heretofore to pass the oil vapors thro'gh the convertingelement or elements at a progressively increasing velocity from theinlet to the outlet terminal portions of such elements. I have observedin the operation of such systems that Where the oil vapors are initiallyintroduced into the converter element, or where the oil vapors are atlowest ternperature, that is temperatures below 1000o Fah., coke orcarbon accumulates rapidly on the walls of the converting element orcatalyst core. This coke or carbon tends to obstruct the free passage ofthe oil vapors through the converting element and also interferes withthe proper transfer of heat from the walls of said element to the oilvapor. In certain instances, however, it has been observed that whenthere is a small amount of'carbon deposit on the Walls of the convertera benecial action is secured in the matter of gasoline recovery and inminimizing the formation of non-combustibles. I attribute this to thefact that the accumulated carbon decreases the effective area of theconverter with the result that the velocity of travel of oil vapor isincreased at the point of oil vapor introduction into the converter. Theincreased velocity results in more rapid heat transference .so that ashorter time ensues in raising the temperature of the (fil vapor to acritical temperature in excess of 10000 Fah. A

It is, therefore, one of the outstanding objects of the presentinvention to provide a vapor phase system of oil conversion wherein thevelocity of travel of the oil vapors in the inlet portions of theconverter is materially greater than that which obtains in the dischargeportions of the converter. This result is secured by controlling theeffective area of the inlet portion of the converter with respect to thecorresponding area of the outlet portion of said converter. By thismanner of operation I am enabled to provide oil vapor velocities ofbetween four to seven thousand feet per minute in the inlet portion ofthe converter and from two to four thousand feet per minute in theoutlet portion of the converter. As stated, by restricting the effectivearea of the inlet portion of the converter, greater velocity is obtainedin this portion of the apparatus, by means of which improved heattransference is procured and the interval of time necessary to raise theoil vapor to a temperature above 10000 Fab. is materially reduced ascompared With constructions providing for uniform flow of the oil vapor.By minimizing the time element in raising the oil vapor to a criticaltemperature I also minimize the release of free carbon or coke from theoil vapor and the resultant deposition of this carbon or coke on thewalls of the converter and catalyst core.

Among several preferred methods of pro.- curing these ends, I have foundit to be most satisfactory to employ a converter consisting of uniformstandard tubes of uniform cross sectional area throughout, and toposition -within such a tube, and in axial relation therewith, a core ofa catalytic material such as molded concrete containing ferrous oxide.This core is of substantially cylindrical form and is so mounted withinthe tubular converting element that there is produced between the wallsof said core and the complement-al inner walls of the tube, an annularspace through which the oil vapor sweeps. I have found that by taperingthe core slightly from the inlet end of the converter element to theoutlet end thereof, a very effective method is sol provided forregulating the area of oil vapor flow through the converter element. Bythis simple expedient I am enabled to obtain any desired velocity of oilvapor flow through any part or parts of the converter element.

For an understanding of the invention reference is to be had to theaccompanying drawing wherein:

Figure 1 is a vertical sectional view taken through an oil heater orconverter formed in accordance with the present invention.

Figure 2 is an enlarged vertical sectional view taken through one of thetubes or elements of the converter provided with a catalytic core.

Figure 3 is a transverse lsectional view on the plane indicated by theline of Figure 2.

Figure l is a similar view taken on the line J-y of Figure 2 through aportion of the core having a smaller diameter.

Referring more particularly to the accompanying drawing, the numeral 1designates an oil heater or converter of the type employed in connectionwith Vapor phase methods of oil decomposition. The heater is formed toinclude the customary setting 2 in which is positioned a vertically andtransversely disposed bridge wall 3, the latter serving to divide theinterior of the setting into burner and tube compartments 4 and 5respectively.

Supported by the walls of the setting 2 and also the bridge 3 are aplurality of converting tubes' 6, the latter being arrangedin rows, withthe upper row of tubes, indicated at B, arranged to pass through thefront and rear 'walls of the setting and also the spaced double walls ofthe bridge 3. The upper row of tubes is connected at its discharge endby means of return bends or header 7 with the next lower row of tubes,and this row of tubes, as well as the remaining rows, are supported lbythe bridge wall 3 and the rear wall of the setting 2. Oil vapor isadapted to enter the v forward end of theA upper row B of tubes 6,

inV order that the oil vapors may be subjected to the developed heatwithin the setting and conversion temperatures in excess of 1000O Fah.secured. If desired, steam may be added to the oil vapors prior to theintroduction of such vapors into the inlet end of the converter.

Arranged within each of the tubes 6, and extending longitudinally andaxially, is a core 8 which is preferably formed from molded concreteimpregnated with ferrous oxide. This core serves as a catalytic orcontact substance during the operation of the system and facilitates orpromotes the desired conversion or actions in the oil body passing invapor form through the converter. The core is supported within the tubeby wire legs 9.

As shown in Figure 2, the core 8 in the upper row B of converting tubesis of tapered form. That is to say, the endof each core 8 at theinletend of the converter is of greater diameter than the end of thecore at the outlet or discharge end of the tube B. In the remainingtubes of the converter the cores may be of uniform diameter, but it isimportant in carrying lout the invention that the cores in the upper rowB of the converter shall be tapered as disclosed. As previouslyexplained, by so forming the core in the first or inlet pass of theconverter the e'ective area for oil vapor travel is restricted, with theresult that the velocity of flow of the oil vapor through the inletportion of the converter is relatively accelerated as compared withthose velocities which obtain in the remaining portions of theconverter. By increasing the velocities heat transference is promotedbetween the-oil vapor and the heated walls of the converter tubes. Thisenables the oil vapors to be readily brought to a critical temperaturewherein the desired reactions take place, and whereinthere is but aminimum deposition of carbon or coke on the walls of the convertertubes. The velocities at the inlet end of the converter range betweenfour to seven thousand feet per minute, while those in the lower rows oftubes of the converter range between two to four thousand feet perminute. The temperature of the oil vapor entering the converter isusually approximately 650o Fah., and this temperature is rapidly broughtto a temperature in excess of 10000 F. in the inlet row of tubes of theconverter. This is due to the fact that accelerated velocities of oilvapor flow exist in the inlet end of the converter tubes, and also dueto the fact that such inlet ends are exposed to the radiant heatdeveloped within the com' bustion chamber of the setting. The oil vaorsdischarged from the converter are rapidly cooled and suitablyfractionated in any standar-d way to condense out motor fuel fractions.

It will be understood that I do not limit myself to the specificconstruction described for securing accelerated'oil vapor flow in theinitial portion of the converting tubes, but reserve the right to employany desired arrangement or other equivalent methods of operation forsecuring the ends desired.

Vhat is claimed is:

1. In a process of refining oil, the improvement comprising passing arapid How of vapors of oil substantially free from hydrocarbonconstituents in the liquid state in a stream of restricted cross-sectionin a series of successive passes through a heater and heating 'the oilvapors during their passage therevio passes of the heater materially inexcess of the vapor velocities which obtain in the succeedin passes ofthe heater, whereby the rate o heat transfer in said initial passes ofsaid conduit to provide for oil vapor iow through said conduit inannular form, said core possessing a greater diameter at one end than atits other and bein arranged within said conduit so that the end thereofof greatest diameter is disposed in the vapor inlet end of said conduit.

In testimony whereof, I aiiix my signature.

CARY R. WAGNER.

the'heater exceeds the rate of heat transfer in s the following passesof the heater.

3. The method of roducin` low boiling point hydrocarbons om hy rocarbonsof relatively h igher boiling points, which consists in passing acurrent of hydrocarbon vapors through an elongated conversion zone ofrestricted cross=section, in so regulating the lflow of the vaporsthrough said zone as to obtain vapor velocities at the entrance por- Ytion of said zone of between four to seven thousand feet per minute, insubse uently reducing these velocities prior to t e discharge thereoffrom said zone to a velocity rate of between two to four thousand feetper minute, and applying heat to the vapors passing through sai zone tosecure vapor temperatures in excess of 1000 F.

4. The method of point hydrocarbons om hy ocarbons of relatively higherboiling points, which consists in passing an annular current of oilvapor through an elongated conversion zone of restricted cross-section,in regulating the effective internal areas ofsaid zone so that thevelocity of 'vapor flow through the entrance ortion of said zone willrange between our to seven thousand feet per minute and in the followingportions of said zone at a velocity range of between two to fourthousand feet per minute, and in heating the oil vapors during passagethrough said zone to conversion temperatures in excess of 1000 F.

5. In an oil converter, an elongated tubular conduit having asubstantially uniform 1n-` ternal diameter throughout the length therevof, and a core of varying cross-sectional diameter arranged to occupy anaxial position within and extending longitudinally of said conduit, thelarger end of said core being disposed in the oil inlet end of saidconduit.

6. In an oil converter, an elongated conduit of restrictedcross-sectional area arranged within the converter through which oilvapor is passed for heating purposes, said conduit possessing asubstantially uniform internal diameter throughout the length thereof,and a core containing iron oxide positioned longitudinally and axiallywithin roducinr low boiling Y

